A semi-empirical LCAO-X-alpha theory of electronic structure is developed and applied to transition metal complexes. Extension to metalloporphyrins will provide energy levels, charge density, and spectral parameters. Resonance Raman spectra of osmium and iron-phenolate porphyrin complexes are examined for excitation profile dependence of axial ligand enhancement with a view to understanding the mechanism of resonance Raman enhancement upon irridation of charge transfer bands. Sterically hindered ferric porphyrins are to be synthesized so as to prevent micro-oxo dimer formation. A likely candidate is tetra-(anthrancyl) porphyrin iron(III). Synthetic modifications will permit covalent linkage with imidazole and pyridine. Syntheses of covalent-linked dimers containing different metals are to be performed in order to study electron transfer mechanisms between porphyrin rings.